Craigslist is refusing to scrap its pet-adoption section over the case of “Puppy Doe,” the young pit bull that was found beaten, burned and left for dead in a Quincy park.

Craigslist CEO Jim Buckmaster wrote in a blog post today that the classified site’s staff was “saddened and horrified” to learn of the “Puppy Doe” case and pledged cooperation with cops hunting for the dog’s tormentor.

But he fired back at a Braintree woman’s petition — nearly 40,000 signatures strong — urging the site to eliminate the pets section, calling her argument “misleading” and saying classified ads, whether in newspapers or online “are not the problem.”

“Many tens of thousands (millions?) of unwanted pets have been rehomed via CL, many if not most of which would have been euthanized, since there is nowhere near the needed capacity in “no kill” shelters — the Humane Society estimates 3-4 million dogs and cats were euthanized in 2009,” he wrote. “In fact, CL “pets” is a (the?) primary tool that shelter volunteers themselves use to find homes for pets they might otherwise have to put down.”

“Monsters do exist and will find victims regardless,” the post continues. “But countless rehomings will become euthanizations if craigslist bows out — giving a few monsters far more destructive power than they deserve.”

“We at craigslist love animals and are proud of the overwhelming good that our ‘pets’ section does in finding new homes for unwanted animals.

“Let’s honor Kiya by (1) not breeding unwanted pets, and (2) taking care when a new home must be found (CL recommends a rehoming fee),” he wrote, calling the dog by the name a previous owner gave it last year.

“Puppy Doe” is the 1- to 2-year-old female pit bull dumped in a Quincy park Aug. 31. The starved, hobbled pup was euthanized, and a necropsy confirmed it had its joints ripped apart in medieval-style torture. It had also been beaten, burned, stabbed in the eye and had its tongue sliced in a serpent-like split.

A woman who owned the dog last year said she both obtained it and gave it away through Craigslist. Quincy cops said yesterday they are working to obtain phone records from either a previous owner or seller as part of their investigation.

Anyone with information on the case is asked to call Quincy ?police at 617-745-5774. Sev­-?eral groups are offering $21,000 in separate rewards for information leading to the abuser’s arrest.